A torque fluctuation absorber is arranged, for example, on a power transmission path between an engine and a motor and absorbs (suppresses) a torque fluctuation between the engine and the motor. A torque fluctuation absorber may comprise a damper unit to absorb a torque fluctuation by a spring power, a hysteresis unit to absorb (suppress) a torque fluctuation by a hysteresis torque such as a friction and a limiter unit to induce a slide when a torsion of a rotating shaft exceeded an absorption capacity of the damper unit or hysteresis unit. Since a torque fluctuation absorber has a plate unfixed or unengaged with respect to a rotating shaft of an engine (crank shaft), rotating shaft of a motor or a piece fixed or engaged therewith, the torque fluctuation absorber has a countermeasure to reduce eccentricity of the plate.
For example, a structure disclosed in FIG. 1 of Patent Document 1 reduces eccentricity of a drive plate (21) by providing a bush (54) that supports the drive plate and a flywheel (10) in a relatively rotatable manner at a gap portion in a radial direction between the drive plate and the flywheel connected with a crank shaft (2) (structure 1).
A structure disclosed in FIG. 2 of Patent Document 1 reduces eccentricity of a drive plate (21) by providing a bush (54) that supports the drive plate and a damper cover (32) in a relatively rotatable manner at a gap portion in a radial direction between the drive plate and the damper cover connected with a crank shaft (2) via a flywheel (10) (structure 2).
A structure disclosed in FIG. 5 of Patent Document 1 reduces eccentricity of a drive plate (21) by arranging a bearing (2b) in a concave portion (2a) at the end of a crank shaft (2) and providing a drive plate supporting member (25) one end of which is fitted into an internal circumference of the bearing and the other end of which is fixed to the drive plate by, for example, welding (structure 3).
In addition, a structure disclosed in FIG. 5 of Patent Document 1 reduces eccentricity of a driven plate (22) by arranging a bearing (2b) in a concave portion (2a) at the end of a crank shaft (2) and providing a driven plate supporting member (26) one end of which is fitted into an internal circumference of the bearing and the other end of which is fixed to the driven plate by, for example, welding (structure 4).
[Patent Document 1]
JP2002-39210A (FIGS. 1, 2 and 5)